mm: migrate: introduce a local variable to get the number of pages

Use thp_nr_pages() instead of compound_nr() to get the number of pages for
THP page, meanwhile introducing a local variable 'nr_pages' to avoid
getting the number of pages repeatedly.

Link: https://lkml.kernel.org/r/a8e331ac04392ee230c79186330fb05e86a2aa77.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: migrate: simplify the file-backed pages validation when migrating its mapping

Patch series "Some cleanup for page migration", v3.

This patchset does some cleanups and improvements for page migration.

This patch (of 4):

There is no need to validate the file-backed page's refcount before trying
to freeze the page's expected refcount, instead we can rely on the
folio_ref_freeze() to validate if the page has the expected refcount
before migrating its mapping.

Moreover we are always under the page lock when migrating the page
mapping, which means nowhere else can remove it from the page cache, so we
can remove the xas_load() validation under the i_pages lock.

Link: https://lkml.kernel.org/r/cover.1629447552.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/df4c129fd8e86a95dbc55f4663d77441cc0d3bd1.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: move kvmalloc-related functions to slab.h

Not all files in the kernel should include mm.h.  Migrating callers from
kmalloc to kvmalloc is easier if the kvmalloc functions are in slab.h.

[akpm@linux-foundation.org: move the new kvrealloc() also]
Link: https://lkml.kernel.org/r/20210622215757.3525604-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm/workingset: correct kernel-doc notations

Use the documented kernel-doc format to prevent kernel-doc warnings.

mm/workingset.c:256: warning: No description found for return value of 'workingset_eviction'
mm/workingset.c:285: warning: Function parameter or member 'folio' not described in 'workingset_refault'
mm/workingset.c:285: warning: Excess function parameter 'page' description in 'workingset_refault'

Link: https://lkml.kernel.org/r/20210808203153.10678-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Merge branch 'akpm-current/current'

Merge remote-tracking branch 'folio/for-next'

# Conflicts:
# mm/filemap.c
# mm/rmap.c
# mm/util.c

Merge remote-tracking branch 'cxl/next'

Merge remote-tracking branch 'rust/rust-next'

Merge remote-tracking branch 'memblock/for-next'

Merge remote-tracking branch 'kunit-next/kunit'

Merge remote-tracking branch 'kgdb/kgdb/for-next'

Merge remote-tracking branch 'auxdisplay/auxdisplay'

Merge remote-tracking branch 'hyperv/hyperv-next'

Merge remote-tracking branch 'nvmem/for-next'

Merge remote-tracking branch 'slimbus/for-next'

Merge remote-tracking branch 'gnss/gnss-next'

Merge remote-tracking branch 'kspp/for-next/kspp'

# Conflicts:
# Makefile

Merge remote-tracking branch 'ntb/ntb-next'

Merge remote-tracking branch 'at24/at24/for-next'

Merge remote-tracking branch 'nvdimm/libnvdimm-for-next'

Merge remote-tracking branch 'rtc/rtc-next'

Merge remote-tracking branch 'coresight/next'

Merge remote-tracking branch 'livepatching/for-next'

Merge remote-tracking branch 'kselftest/next'

Merge remote-tracking branch 'userns/for-next'

Merge remote-tracking branch 'pwm/for-next'

Merge remote-tracking branch 'pinctrl/for-next'

Merge remote-tracking branch 'gpio-brgl/gpio/for-next'

Merge remote-tracking branch 'rpmsg/for-next'

Merge remote-tracking branch 'vhost/linux-next'

# Conflicts:
# drivers/virtio/virtio.c
# include/uapi/linux/virtio_ids.h

Merge remote-tracking branch 'scsi/for-next'

# Conflicts:
# drivers/scsi/st.c

Merge remote-tracking branch 'cgroup/for-next'

Merge remote-tracking branch 'dmaengine/next'

Merge remote-tracking branch 'vfio/next'

Merge remote-tracking branch 'extcon/extcon-next'

Merge remote-tracking branch 'usb/usb-next'

Merge remote-tracking branch 'ipmi/for-next'

Merge remote-tracking branch 'chrome-platform/for-next'

Merge remote-tracking branch 'drivers-x86/for-next'

Merge remote-tracking branch 'percpu/for-next'

Merge remote-tracking branch 'xen-tip/linux-next'

Merge remote-tracking branch 'kvms390/next'

Merge remote-tracking branch 'kvm-arm/next'

Merge remote-tracking branch 'kvm/next'

Merge remote-tracking branch 'rcu/rcu/next'

# Conflicts:
# kernel/time/tick-internal.h

Merge remote-tracking branch 'ftrace/for-next'

# Conflicts:
# MAINTAINERS

Merge remote-tracking branch 'tip/auto-latest'

Merge remote-tracking branch 'mailbox/mailbox-for-next'

Merge remote-tracking branch 'devicetree/for-next'

Merge remote-tracking branch 'iommu/next'

Merge remote-tracking branch 'watchdog/master'

Merge remote-tracking branch 'keys/keys-next'

# Conflicts:
# certs/system_keyring.c

Merge remote-tracking branch 'integrity/next-integrity'

Merge remote-tracking branch 'apparmor/apparmor-next'

Merge remote-tracking branch 'security/next-testing'

Merge remote-tracking branch 'backlight/for-backlight-next'

Merge remote-tracking branch 'mfd/for-mfd-next'

Merge remote-tracking branch 'block/for-next'

Merge remote-tracking branch 'input/next'

Merge remote-tracking branch 'modules/modules-next'

Merge remote-tracking branch 'imx-drm/imx-drm/next'

Merge remote-tracking branch 'amdgpu/drm-next'

# Conflicts:
# drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c

Merge remote-tracking branch 'drm-misc/for-linux-next'

Merge remote-tracking branch 'nand/nand/next'

Merge remote-tracking branch 'mtd/mtd/next'

Merge remote-tracking branch 'bluetooth/master'

Merge remote-tracking branch 'rdma/for-next'

Merge remote-tracking branch 'swiotlb/linux-next'

# Conflicts:
# kernel/dma/direct.c

Merge remote-tracking branch 'dlm/next'

Merge remote-tracking branch 'ieee1394/for-next'

Merge remote-tracking branch 'thermal/thermal/linux-next'

Merge remote-tracking branch 'cpupower/cpupower'

Merge remote-tracking branch 'pm/linux-next'

Merge remote-tracking branch 'v4l-dvb-next/master'

Merge remote-tracking branch 'jc_docs/docs-next'

Merge remote-tracking branch 'i2c/i2c/for-next'

Merge remote-tracking branch 'hid/for-next'

Merge remote-tracking branch 'pstore/for-next/pstore'

Merge remote-tracking branch 'pci/next'

# Conflicts:
# MAINTAINERS
# drivers/net/ethernet/broadcom/bnx2.c
# drivers/net/ethernet/broadcom/bnxt/bnxt.c

Merge remote-tracking branch 'printk/for-next'

# Conflicts:
# MAINTAINERS

Merge remote-tracking branch 'vfs/for-next'

Merge remote-tracking branch 'zonefs/for-next'

Merge remote-tracking branch 'xfs/for-next'

Merge remote-tracking branch 'v9fs/9p-next'

Merge remote-tracking branch 'overlayfs/overlayfs-next'

Merge remote-tracking branch 'ntfs3/master'

Merge remote-tracking branch 'cel/for-next'

Merge remote-tracking branch 'nfs-anna/linux-next'

Merge remote-tracking branch 'fuse/for-next'

Merge remote-tracking branch 'f2fs/dev'

Merge remote-tracking branch 'ext4/dev'

Merge remote-tracking branch 'ext3/for_next'

Merge remote-tracking branch 'erofs/dev'

Merge remote-tracking branch 'configfs/for-next'

Merge remote-tracking branch 'btrfs/for-next'

Merge remote-tracking branch 'fscache/fscache-next'

Merge remote-tracking branch 'pidfd/for-next'

Merge remote-tracking branch 'xtensa/xtensa-for-next'

Merge remote-tracking branch 'uml/linux-next'

Merge remote-tracking branch 'sh/for-next'